Miyoshi Umeki, a Japanese-born singer and actress who became the first Asian performer to win an Academy Award, for “Sayonara” (1957), distinguished herself onstage in “Flower Drum Song” and played a housekeeper on the TV series “The Courtship of Eddie’s Father,” died Aug. 28 at Licking Park Manor nursing home in Licking, Mo. She had cancer and was 78.

“Sayonara,” based on a best-selling James Michener novel, was about forbidden romance between U.S. servicemen and Japanese women during the Korean War. Ms. Umeki’s naive character marries an Air Force sergeant, played by Red Buttons, and the relationship leads to his persecution and their double suicide. Ms. Umeki and Buttons won Oscars for their supporting parts.

For much of the 20th century, movies or plays featuring Asian characters used actors without accounting for the distinctions among various ethnic groups. Ms. Umeki’s work ethic overrode any concerns about playing the Chinese mail-order “picture bride” Mei Li during the Broadway run of “Flower Drum Song” (1958).

The Richard Rodgers and Oscar Hammerstein musical, in part about assimilation to American life, lasted two years onstage and brought Ms. Umeki a Tony Award nomination for best actress in a musical.

“The warmth of her art works a kind of tranquil magic, and the whole theater relaxes,” Time magazine wrote in a cover story about her and co-star Pat Suzuki.

Ms. Umeki repeated the role of Mei Li in the 1961 film version of “Flower Drum Song” and appeared in a handful of mediocre east-meets-west romances, comedies and dramas, including “Cry for Happy” with Glenn Ford, “The Horizontal Lieutenant” with Jim Hutton and “A Girl Named Tamiko” with Laurence Harvey.

She gladly retired in 1972 after a three-year stint on ABC’s “The Courtship of Eddie’s Father.” The sitcom, starring Bill Bixby, was based on a Glenn Ford film about an urbane widower being set up on dates by his son.

Ms. Umeki was born May 8, 1929, in Otaru, on the northern Japanese island of Hokkaido, where her father owned an iron factory.

Under the name Nancy Umeki, she recorded U.S. pop standards for RCA Japan before arriving in the United States in 1955 and signing with Mercury Records. A recurring engagement on Arthur Godfrey’s television show brought her to the attention of Joshua Logan, director of “Sayonara.”

Her marriage to television executive Frederick Opie ended in divorce. Her second husband, documentary producer-director Randall Hood, whom she married in 1968, died in 1976.

Survivors include a son from her second marriage, Michael Hood, of Licking; a sister; and two grandchildren.

Ms. Umeki withdrew from public life after “The Courtship of Eddie’s Father” ended its run. She co-owned and operated a business renting editing equipment before moving to Missouri from North Hollywood, Calif., five years ago. The only time she performed was about four months ago, when she taught her granddaughter a Japanese song.